1. Field of the Invention
The present invention relates to a micro manipulator that can be used in biotechnology, medicine, semiconductor integrated-circuit manufacture/inspection, and other industrial applications which require micro-operations, and more particularly to a micro manipulator capable of performing micro-operations accurately and easily, such as the positioning, transfer, cutting, and bonding of very small objects, or suitable for application to an accurate sample-mounting stage positioning mechanism or the like.
2. Prior Art
An example of a 3-DOF (three-degree-of-freedom) micro manipulator suitable for the micro-operations under a microscope is described in Japanese Application Patent Laid-Open Publication No. Hei 10-138177 (published in 1998).
The above prior art relates to a 3-DOF micro manipulator that was developed with focus placed on the fact that during the micro-operations under a microscope, parallel 3-DOF operation in three axial directions orthogonal to each other is the main operation of the micro manipulator. Three link mechanisms for connecting the base and end effector of the micro manipulator are provided to implement 3-DOF accurate positioning control of the end effector.
The above link mechanisms have revolving joints (rotating pair) and prismatic joints. These joints are combined into 4-DOF link mechanism as an RRPP mechanism (R and P stand for revolving joint and prismatic joint, respectively), RPRP mechanism, PRPR mechanism and RPPR mechanism. Three such 4-DOF link mechanisms are arranged in parallel, in order to enable the end effector to operate with three degree of freedom. Also, the flexure (flexible) hinge portions of the revolving joints and the connecting link portions of the prismatic joints are thinned down at both ends of each portion to ensure that the revolving joints and the prismatic joints accomplish their intended purposes.
The above-described prior art has the advantages that the flexure hinge portions or the like requires no ball joints or the like and that the simplification of components, and even of the mechanisms, can be achieved. However, detailed methods are not proposed about how the flexible structure for constituting the link mechanisms of the micro manipulator can be manufactured at lower costs and into smaller dimensions, about what type of material should be used for the structure, or about the layout of the actuators to be used to form a driving mechanism for the structure. The use of piezoelectric elements in the driving mechanisms for each link is proposed.